The objective of this application is to improve measurement of the intensity and functional aspects of pain by developing a novel assessment method and demonstrating its feasibility in both acute and chronic pain patients. The new approach asks the patient to use a highly intuitive interface [the Visual Time Analog (VITA)] to partition the time spent in mutually exclusive, clinically valid pain states. The partitions provided by the patients generate ordered categorical response states that have very desirable psychometric and statistical properties, and which will be suitable for individual clinical monitoring as well as trial endpoints. The devices will generalize the Visual Analog Scale interface by allowing patients to move sliders back and forth along an unruled scale. After optimizing response formats and categories in pilot testing, we will demonstrate feasibility by conducting evaluations of 200 Emergency Department patients with acute pain and 30 patients from a tertiary pain management center with chronic noncancer back pain. To demonstrate sensitivity to change, we will collect repeated assessments in both settings. We will establish proof of concept by demonstrating that the novel approach outperforms the VAS standard on objective measurement criteria. Patients will appreciate the simplicity and elegance of the interface. Clinicians will value the improved portrayal of how individuals differ, how they change over time, and the increased ability to predict important clinical events from these more sensitive measures. Statisticians will appreciate the principled modeling of ordered response categories and the range of qualitative and continuous analytic options the new scales permit. PUBLIC HEALTH RELEVANCE: The objective of this application is to develop a new method of pain measurement that divides the day into the lengths of time spent in minimal or intense pain states. The new method lets the patient use simple sliders to indicate response, but leads to scoring and measurement that is valid, reliable, and sophisticated.